1. Related Application
The present invention in related to U.S. Pat. Ser. No. 121,088 of Henry C. Abbink and Nicholas F. Pier entitled "Integrated Accelerometer Assembly" which was filed on Nov. 16, 1987, now U.S. Pat. No. 4,987,780.
2. Field of the Invention
The present invention relates to integrated accelerometers. More particularly, this invention pertains to an integrated accelerometer that includes a number of improved sub-assemblies for effecting enhanced accuracy and durability.
3.Description of the Prior Art
Accelerometers of the hinged, pendulous mass type have substantially replaced floated accelerometers in modern strapdown inertial navigation systems. Such hinged accelerometers offer smaller size, lighter weight and simplified construction. Functionally, a common type of single axis accelerometer comprises a pendulous mass that is suspended within a housing by flexure type hinges. When subjected to acceleration, the mass pivots or rotates about the hinge axis to thereby shutter the output of a light-emitting diode (LED) that is conventionally located adjacent to the mass' non-pivotal or "free" end. This is detected by a photodetector circuit. The circuit produces an output signal that is proportional to the sensed acceleration. Such signal is amplified and the resultant current is applied to a torquer coil that is mounted to the pendulous mass. The coil reacts with a permanent magnet that is affixed to the housing to return the mass to a substantially neutral (null) position. The torquing current provides a measure of the input acceleration.
While the foregoing arrangement may provide excellent performance in a relatively small package, its manufacture requires intensive manual assembly and adjustment resulting in substantial expense. Conventional designs include minute components that are attached by Epoxy or solder in processes that require highly dexterous and skilled personnel.